Archaeology Notes

A broch which MacKie dates to the very early 1st century AD (MacKie 1965a) and a cairn on neighbouring island which the OS connects by a causeway, no signs of which are now visible. According to Spence the broch was 'connected with the land by a bridge of large stepping-stones over which the sea flows at full tide.'(Spence 1899) The site is now inaccessible without a boat except at very low tide. Much of the ground plan of the broch can still be made out, but many details are obscured by fallen material. Although the outer face has collapsed on the N.E. and the south, it still stands eight or nine courses high elsewhere. The overall diameter is 58' and the walls average 15' in thickness. The cairn is greatly dilapidated. The RCAHMS express extreme doubt as to the connection between the broch and the cairn.

RCAHMS 1946

The islands are connected 'by a stone causeway erected over a series of conduits'.

Name Book 1878.

A broch as described and illustrated by the RCAHM, accessible at low water by a well-built causeway. There is no trace of a cairn on the islet some 70.0m ESE of the broch. The islet is greatly eroded down to bed rock and only a little vegetation remains on its summit. An unlikely situation for a cairn.

Activities

Probable aberrant ground-galleried broch of unusual form in Sandsting, Mainland, standing on a low rocky islet firth (the Holm of Hebrista) in the Firth (Ills. 4.15-20). According to Spence there was once a causeway from the islet to the shore; although not seen by the Commission's investigators [2] it was apparent at low water in 1969 [1]. The site is an interesting one in that in its structure and situation it strongly resembles an island broch in the Outer Hebrides, even to the extent of having the ledge type scarcement which is rare in Shetland but almost universal in the west. The local stone also splits into massive polygonal blocks, like the gneisses of the Outer Hebrides.

George Low visited the site "'on a small holm in Helinster Voe ..... called the Burgh of Burrafirth." He described a number of cells in the base of the wall (the diagram showing the impossible number of eleven) 'to be entered from within' (i.e. from the court) and clearly stated that the hollow, galleried wall began above these. Moreover the description could imply that there was more than one gallery preserved at that time, namely "the double wall with galleries began above these" (the cells) "and was continued to the top". The cross section suggests a wall height of about 15 ft. just over two centuries ago (Ill. 4.143).

In spite of much fallen debris a number of structural features were made out, although there is no sign now of the upper gallery mentioned by Low. The entrance is blocked with stones but the lintel over the inner end is apparent (Ill. 4.16, above the theodolite), at the level of a scarcement 9-11 ins. wide which runs all round the interior at an unknown height above the floor (Ill. 4.17). Voids are visible over the main entrance, and over the doorways to four mural cells (Ill. 4.18); these should have led to an upper gallery.

These cells are of unusual construction, two being dumb-bell shaped with short passages between the two halves. Another seems to be an elongated cell reached by a short length of gallery from a doorway (see HU15 1 above) and one of the dumb-bells is similarly reached by a length of gallery into one end from a doorway as well as through a second doorway at its centre point (Ill. 4.20). A fourth mural cell seems to be circular and its entrance is not visible. There appear to be two cells on either side of the entrance passage, almost certainly guard cells (Ill. 4.19).

Dimensions. External diameter 58 ft. and wall thickness about 15 ft.: the walls proportion is therefore about 51.7%. In 1987 a fresh survey of the central court (below scarcement level) was made by the author which revealed that in plan it was close to a true circle with a radius of 4.10 +/- 0.08 m; the diameter is thus close to 8.20 m (26.89 ft.).